Zinc-enriched biomass, method for the preparation thereof and pro-biotic, cosmetic, dietary and nutraceutic products comprising the same

Abstract

The invention relates to a zinc-enriched biomass comprising living or subsequently killed micro-organisms, selected from the group consisting of Streptococcus thermophilus and Bifidobacterium animalis subsp. lactis and combinations thereof, a method for the manufacture of said zinc-enriched biomass, as well as food preparations, nutraceutic products, functional foods, cosmetic and cosmeceutic products, and food supplements, comprising the said biomass. Furthermore, new micro-organism strains are described which are able to concentrate zinc within the cell in very high amounts and therefore are particularly suitable for use in the method of the invention.

The invention claimed is: 
     
       1. A method of preparing a zinc-enriched biomass, the method comprising:
 (i) culturing micro-organisms selected from the group consisting of  Streptococcus thermophilus  ST 16 BM, deposited under the Budapest Treaty at the DSMZ, Braunschweig, Germany, under the accession number DSM 19526 on Jul. 13, 2007, and  Bifidobacterium animalis  subsp. lactis BB 1 BM, deposited under the Budapest Treaty at the DSMZ, Braunschweig, Germany, under the accession number DSM 17850 on Dec. 23, 2005, and combinations thereof, in a nutrient culture medium comprising a zinc salt in a concentration of between 5 to 50 mM, to obtain zinc-enriched micro-organisms; and 
 (ii) separating the zinc-enriched micro-organisms from the culture medium. 
 
     
     
       2. The method according to  claim 1 , wherein the micro-organisms separated from the culture medium are subjected to freeze-drying, drying, micro-encapsulation and/or freezing. 
     
     
       3. The method according to  claim 1 , wherein the zinc salt is zinc sulphate. 
     
     
       4. The method according to  claim 1 , wherein the culture medium is a liquid medium. 
     
     
       5. The method according to  claim 1 , wherein the culture medium comprises conventional nutrients for the growth of said micro-organisms, selected from the group consisting of carbon, nitrogen, vitamins, and additional inorganic salts and micro-nutrient sources, and mixtures thereof. 
     
     
       6. The method according to  claim 1 , wherein said culture medium has a pH in the range from 2.5 to 8.0. 
     
     
       7. The method according to  claim 1 , wherein said micro-organisms are cultured in said culture medium at a temperature in the range from 25° C. to 48° C. 
     
     
       8. The method according to  claim 1 , wherein said micro-organisms are cultured in said culture medium for 6 to 40 hours. 
     
     
       9. The method according to  claim 1 , wherein said micro-organisms are separated from the culture medium by centrifugation or micro-filtration. 
     
     
       10. The method according to  claim 3 , wherein the nutrient culture medium comprises a zinc sulphate amount in the range from 10 to 40 mM. 
     
     
       11. The method according to  claim 1 , wherein said culture medium has a pH in the range from 3.5 to 7.5. 
     
     
       12. The method according to  claim 1 , wherein said micro-organisms are cultured in said culture medium at a temperature in the range from 35° C. to 45° C. 
     
     
       13. The method according to  claim 1 , wherein said micro-organisms are cultured in said culture medium for 8 to 36 hours. 
     
     
       14. A method of preparing a zinc-enriched biomass, the method comprising:
 (i) culturing micro-organisms selected from the group consisting of  Streptococcus thermophilus  ST 16 BM, deposited under the Budapest Treaty at the DSMZ, Braunschweig, Germany, under the accession number DSM 19526 on Jul. 13, 2007, and  Bifidobacterium animalis  subsp. lactis BB 1 BM, deposited under the Budapest Treaty at the DSMZ, Braunschweig, Germany, under the accession number DSM 17850 on Dec. 23, 2005, and combinations thereof, in a nutrient culture medium comprising a zinc salt in a concentration of between 10 to 40 mM, to obtain zinc-enriched micro-organisms; and 
 (ii) separating the zinc-enriched micro-organisms from the culture medium.